What would be required to build a headless Overbridge Mini Computer for individual outputs?

My Digitone Keys’ individual outputs makes me terribly want discrete outputs from my Digitakt but I use iOS as my recording device/mixer/mobile computing which of course overbridge does not exist on. It got me wondering, and forgive me as I’m not well learned regarding Rasp Pi’s and the like, but shouldn’t it be possible to build a small, relatively cheap headless computer interfacing with an 8 channel USB sound card that when powered on, it boots up, and automatically launches a preconfigured Overbridge session that sends the Digitakts 8 individual outputs to the interface outs? How fast of a system would be required to do that with reasonable latency? Would any fairly recent ‘mini’ computer handle it? Surely windows could be configured to run that on boot without interaction?

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Not practical because latency.

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Not necessarily. If you use the digitakt as audio interface and stream directly into a daw that way you’ll have low latency. So without the plugin. I’m not sure raspberry pi can handle audio very well. Or it does but needs an extension of some sorts. Not really into that so can’t help in that regard :slight_smile:

Brilliant. And I believe I recently read about some interfaces without any mix software that tout amazing latency? Perhaps even Presonus? Though a tech friend did some testing in order to build an ultrafast drum triggering rig for a tour he was hired onto this last summer and I believe even that lost out to…an Apollo, was it? In any case, I think it’s perfectly possible. If it can be done with a digitakt, interface/outputs, a desktop PC, monitor, mouse, and keyboard; it can be setup to do the same upon boot with only necessary hardware and OS/drivers. I thought there was a recent PI released that might be able to handle it with some additions, as you mentioned @DaveMech, but I’m not sure. If not, I’m curious if anybody knows what kind of specs might be necessary or could recommend a model to try? 8 unprocessed/direct thru tracks really isn’t a big ask. I wonder how bare bones of a system could manage it!

latte panda alpha can run hackintosh but its expensive, i read somewhere a while ago that someone made the multichannel capabilities of the elektron machines work on linux, you should be fine on a headless rpi with custom / realtime kernel and a multi out interface, either external but preferably something gpio friendly since you are more likely to have really low latency this way

Thank you @ylva! I understand most of those terms, :rofl: I will look into it during this slow season!

The raspberry pi can’t run any version of Windows on which you can install Electron’s drivers so that’s kinda irrelevant.

It’s true that not using the plugin gives you lower latency, but still not something low enough to make a lot of sense in a live environment.

Anyway, just give it a try with your current computer. If it works for you, move the setup to a NUC with automatic login to make it headless.

But again, you’re going to introduce significant latency.

Eh? Let’s keep it factual though :slight_smile: I hear you regarding pi.

However, using DT as an audio interface at 64 buffer (or 32 even) you certainly get low enough latency to play live with it, just like with any modern audio interface. Arguably even at 128.

Using the plugin you get around 20ms last time I checked. Using it as audio interface without the plugin you will get below 7ms round-trip. That’s not unusable in a live situation at all. Think you can go lower even.

It’s not just the input buffer on your computer, but the latency from the output buffers in the Digitakt plus the input buffers on your computer plus the output buffering from your audio interface.

Maybe I’m being overly pessimistic. The only way to find out is for @dreamsaremaps to give it a try! :slight_smile:

The nice thing is that you can test this on your regular computer before you invest in a tiny one.

EDIT: You can easily measure roundtrip latency for whatever by using any external audio recorder. In this case you’d connect the direct signal from your DT to the L input on that recorder and the roundtripped signal from your DT through your computer into your audio interface to the R input. Then look at that stereo recording in an audio interface and measure the distance between the same transients in the L and R channel.

I think you are misunderstanding me maybe.
You don’t need another audio interface. DT is the audio interface. That’s why I explicitly said ‘without the OB plugin’. :wink:

Ps. To be fair, on my laptop I get the round-trip latency as low as 10ms and not lower. Which is not super. On my desktop I get better results.

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No, I get you. :slight_smile:

You still need Elektron’s drivers to use Overbridge devices as a regular audio interface on your computer as they’re not class compliant (with the Heat as a recent exception).

Using Overbridge devices as your primary audio input device indeed gives you lower input latency compared to using the plugin, but they were never designed to be as low-latency as possible for live tracking.

You will need another audio interface for those 8 individual outputs.

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In fairness, it may very well depend on what definition of ‘live performance’ each of us is using. Or should I say live tracking? I didn’t actually mention either. Currently, I (and I’d imagine many of us) willingly add some latency in turn for desired features. I also tolerate more latency during mixing and arranging and general tweaking than I do during acoustic tracking, etc. Trade offs, and all that. Someone finger blasting 180 BPM 1/64th notes into a sequencer of equal resolution will have a different acceptable latency than someone twiddling some knobs and changing patterns like scenes, and in between those 2 probably fall most of us to varying degrees. Besides, some of us grew up cobbling together dumper electronics, poor choices, and MIDI cables creating such horribly convoluted workflows that, sadly, out of necessity, we eventually learned how to compensate for painful obvious shoes in a dryer style, “which one’s the ‘1’?“ latency. Noticeable latency is absolutely manageable for some types of performance, for instance, centered around pattern launching.

But sure, it may not be perfect of even useable for all techniques, and it may be disorienting and unusable to folks sensitive to or not used to it, but there are other use cases even with heavy latency, for instance if I want to process the 8 drums of a kit through different fx paths of a small euro rack case without a laptop, for either performance or tracking use. You know, on the side of a cliff or, whatever…

Or if I wanted to record discrete outputs of my patterns for later processing and mixing on the go and didn’t own a laptop, because, that’s something I wish I could do, and something I currently can’t. Not on iOS. And I don’t want to buy a laptop. I already have a traditional computer and I’ve spent the last 10 years trying to break free from it.

So I know I can do all these things on my current system. What I’d like to gain some understanding of is what parts/choices/software/etc will influence which results/factors, weigh those options, decide on something reasonably affordable that has a decent chance of providing some level of vaguely known usability to me, and seeing what happens, and what I end up able to get out of it, and if its worth learning from and revisiting.

What I had been thinking would indeed require another interface, another added trip of latency, but if sent straight to hardware only from there, I think could coexist in some cases with plenty of other performance techniques. But after hearing of hijacking the audio stream, no additional card would be required just to capture multi output takes, and that’s useful too. Jamming out on the digitakt and remixing/arranging/mixing/whatever later with discrete tracks is actually the only use I have for overbridge and a desktop (aside from the digitakt transfer app, another hurdle I’d like to tackle with the same piece of headless gear), and I’d much rather just have it be a little square with a button on it rather than a bulky laptop. Hell, let’s add the Digitone into the mix! I have the keys version with independent outs, but for portability the standard DN is much more convenient. But, it’d be a lot better if it were both portable and easily multi tracked for later!

Thanks for the ideas and links, everyone. Apparently I’ve got some learning to do.